Background and Aim: Few studies have assessed the reliability of postural balance measures during dynamic balance performance that introduce additional challenging to postural control system. In addition sometimes in the static conditions some deficiencies of the postural control system may not be revealed obviously therefore the aim of this study was to assess the reliability of postural control parameters during functional performance on force plate in healthy subjects.
Materials and Methods:  Ten healthy male subjects (mean age: 25.4 years, weight: 68.2 kg height:176.9cm) participated  in this study. None of the subjects were involved in sport activities. Every subject performed three 15seconds trials of eyes open single leg stance on a force plate during dynamic balance task. Participants grasped object with hand at their waist level and release it at above shoulder level.  The reproducibility of the center of pressure (COP) deviations (average speed &length of path) was assessed. All participants were tested on 2 sessions with an inter-measurement interval of 7 days. COP data was collected for each trial. The intraclass correlation coefficient (ICC) was used as parameter of intra-session and inter-session (Test-Retest) reliability.
Results: The ICCs for intra-session reliability of average speed and length of COP path were  0.89 and 0.91  respectively. The ICCs for inter-session reliability were 0.95 and 0.96 respectively.
Conclusion: The study showed high and very high reliability for center of pressure measures during dynamic balance task. Therefore this dynamic performance can be used as a balance pattern in postural control assessment. These can be used as reliable parameters in dynamic postural control assessment due to high reliability of average speed and length of COP path

Background and Aim: Having a proper posture is one the aspects of good health which has important role in activity of daily living and sport skills. Spine abnormality is the most prevalent disorder and hyperkyphosis is more propagated one. The purpose of present study was to compare the effect of conventional corrective exercise and physioball exercise on improvement hyperkyphosis and vital capacity in girl students.

Materials and Methods: 44 girl students (13±0.83 age) with the hyperkyphosis were participated in this study. Participants did not have any history of surgery, trauma or pain in their limbs. In pre-test and post-test, curvature of the back  measured by a flexible ruler and  vital capacity measured by a digital spirometer.

 Students in terms of the curvature of the back were divided in to three subgroups of experimental 1 (Corrective exercises physioball), experimental 2 (conventional corrective exercise), and the control group (did not participated in any exercise program). The training program was done eight weeks, 3 times per week.

Results: The result of ANOVA showed that there are significant differences between pre-test and post-test. The results of Tokey showed that there are significant differences between both experimental groups compare to control group in hyper kyphosis and vital capacity in post-test. However there is not different between 1 and 2 experimental groups (P≥0/05).

Conclusion: Performance training with physioball and without physioball are useful for improvement of hyperkyphosis and vital capacity in young female students. There is not different between two groups.

Key words: Corrective exercise, Vital capacity, Physioball,  Hyperkyphosis